Speed wobble = crash!

I was decending on a 17% single track road in Wales at 45mph when it began. I'm a pretty experinced cyclist and I have read up about how to combat speed wobble if it ever was to occur but when it actually happens to you it's a different story.

I tried holding the top tub between my knees, releasing both brakes, only using my back break but nothing worked and it got progressively worse until the road curved round the the left I couldn't stear and went straight on into a ditch at 40mph!

I managed to total trash my nice hand built wheels and break my helmet in half. Spent most of the afternoon in hospital, nothing broken (luckly) but I do feel like I've been dropped from a great height.

I've discovered that 34's my limit after having had my wheels skip sideways while sprinting after a car (I was trying to keep up with a couple of old dears barely doing 30 in an NSL area). That was definitely squeaky bum time... :shock:

Speed wobble is basically a speed induced instability in the bike which happens at a speed which is determined by your bike geometry. its basically where the bike starts to become unstable due to the coupling between the bike the rider and the road and it can mean that the bike is uncontrollable. In theory it can be stopped by simply letting go of everything so the rider isn't as tightly coupled to the bike and it breaks the feedback loop, in practice when it happens and you are doing 40+ downhill and you suddenly cannot steer letting go of everything is virtually impossible.
it motorbiking its called a death wobble or a tank slapper because the handlebars swing so wildly that they hit the fuel tank.

The gear changing, helmet wearing fule.
FCN :- -1
Given up waiting for Fast as Fupp to start stalking me

I was going south at Llanymawddwy in the Snowdonia national park. There are some seriously steep hills round there. The speed came very quickly and by the time I thought hey I'm going to quickly it was to late.

I'm not quite sure what insurance I could claim on but I pick up a new winter bike tomorrow so I'll probably leave it now until the spring.